This dissertation is concerned with the contentious issue of treating buildings of the recent past as part of a common architectural heritage to be protected. Specifically, it is concerned with issues of environmental compatibility, economic feasibility and social viability in the built environment. After an initial investigation of the topic generally, the research identifies the most pressing issues arising from the conservation of modernist heritage, whilst analysing key international cases emblematic of the Modern Movement. This approach develops a series of constructive observations that are intended to question the current conservation practice and that ensure that over-arching objectives of sustainability are met. A particular focus is given to recent practice in the U.K. Policies are considered in the light of the current theoretical and legislative framework, particularly highlighting English Heritage’s recent move since the late 1990s towards a more sustainable, integrated practice on post-war heritage. Originating from the theoretical roots of ‘Conservazione Integrata’, an Italian concept that was later promoted by the Council of Europe with the 1975 Charter of Architectural Heritage, the current idea of ‘Planned and Integrated Conservation’ has gradually replaced the traditional concept of restoration and preservation, whilst also facing the emerging dispute over sustainability. Through my research, I have investigated the discourse within international socially embedded contexts, where architectural heritage represents a source of social, environmental and economic values to be preserved and passed on to future generations.